The Dutch king, Willem-Alexander, has apologised for the Netherlands’ historical involvement in slavery and the effects that it still has today. The king was speaking in Amsterdam on the 160th anniversary of the legal abolition of slavery in the Netherlands, including in former colonies in the Caribbean. In an emotional speech, he said: “On this day that we remember the Dutch history of slavery, I ask forgiveness for this crime against humanity. As your king and as a member of the government, I make this apology myself. And I feel the weight of the words in my heart and my soul.” He said racism in Dutch society was still a problem and not everyone would support his apology. However, “the times have changed and keti koti … the chains have truly been broken,” he said to cheers and applause from thousands of onlookers at the national slavery monument in Oosterpark. Keti koti are Surinamese words that mean “the chain is broken” and form the name given to 1 July as a day of remembrance of slavery and celebration of freedom. Slavery was abolished in Suriname and the Dutch colonies in the Caribbean on 1 July 1863, but many enslaved labourers were forced to continue working on the plantations for a further decade. The king’s apology comes amid a wider reconsideration of the Netherlands’ colonial past, including involvement in the Atlantic slave trade and slavery in its former Asian colonies. In 2020, Willem-Alexander apologised in Indonesia for “excessive violence” during Dutch colonial rule. In December, the prime minister, Mark Rutte, acknowledged that the Dutch state bore a responsibility in the Atlantic slave trade and had profited from it, and apologised. However, Rutte has said the government will not pay reparations, contrary to recommendations made by an advisory panel in 2021. Last year, Willem-Alexander commissioned a study into the role of the royal House of Orange-Nassau in slavery in the Netherlands, covering the period from the late 16th century to today. The results are expected to be announced in 2025. A study published last month found that the House of Orange profited by the equivalent of about $600m in today’s money from slavery in the Dutch colonies from 1675 to 1770, including profits from shares in the Dutch East India Company that were in effect given to the royal family as gifts. The British royal family were given at least one similar gift, the Guardian revealed in April. A document published by the Guardian shows that £1,000 of shares in the Royal African Company (RAC) were transferred to William III in 1689 from Edward Colston, the company’s now notorious deputy governor. The RAC captured, enslaved and transported thousands of African people after it was established in 1660 by the House of Stuart and City of London merchants to trade along the west African coast. Further reporting by the Guardian revealed that the direct ancestors of King Charles III and the royal family bought and exploited enslaved people on tobacco plantations in Virginia. A newly discovered document showed that a direct ancestor of the king and the late queen mother, a Virginia tobacco plantation owner called Edward Porteus, was involved in buying at least 200 enslaved people from the Royal African Company in 1686. In response to the Guardian’s reporting, Charles signalled for the first time his support for research into the links between the British monarchy and the transatlantic slave trade. A Buckingham Palace spokesperson said at the time that Charles took “profoundly seriously” the issue of slavery, which he has described as an “appalling atrocity”. Support for the research was part of Charles’s process of deepening his understanding of “slavery’s enduring impact”, the spokesperson said. They added: “As part of that drive, the royal household is supporting this research through access to the royal collection and the royal archives.”